Fatty Liver Index as a proxy for non-alcoholic fatty liver disease and the risk of stroke and coronary heart disease: The Suita Study

Background: Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in developed countries, but its role in predicting cardiovascular disease (CVD) needs further investigation. Herein, we studied the association between NAFLD and the risk of CVD, stroke, and coronary heart disease (CHD) among Japanese people.Methods: This prospective cohort study analyzed data from 2,517 men and 3,958 women, aged 30-84 years, who were registered in the Suita Study. NAFLD was defined as Fatty Liver Index (FLI) > 60. Cox proportional hazard models were applied to calculate the hazard ratios (HRs) and 95% confidence intervals (95% CIs) of incident CVD, stroke, and CHD events by baseline FLI. The results were adjusted for age, smoking, alcohol consumption, hypertension, diabetes, lipid profile, chronic kidney disease, and cardiac murmur or valvular diseases.Results: Within 16.6 years of median follow-up, 590 participants developed CVD (346 stroke events and 244 CHD events). Women with NAFLD (FLI >= 60) showed a higher risk of CVD and stroke: HRs (95% CIs) = 1.69 (1.16, 2.46) and 2.06 (1.31, 3.24), respectively. Besides, women in the fourth and fifth (highest) FLI quintiles showed a higher risk of CVD and stroke than those in the third (middle) quintile: HRs (95% CIs) = 1.60 (1.08, 2.36) and 1.67 (1.13, 2.45) for CVD and 1.73 (1.07, 2.79) and 1.90 (1.18, 3.05) for stroke, respectively. No corresponding associations were detected in men. NAFLD was not associated with CHD risk in either sex.Conclusions: NAFLD, diagnosed by FLI, was associated with a higher risk of CVD and stroke in Japanese women. From a preventive perspective, women with NAFLD should be targeted for CVD screenings and interventions.